Subanalysis of clinical trials, and real-world data, demonstrate that EGFRs with defined, but uncommon mutations such as G719X, S768I, and L861Q are sensitive to afatinib, which is now approved for tumors harboring these mutations.
Through an evolutionary analysis of the sequencing results, the EGFR p.L861Q mutation was determined to play a role in the progression from the primary tumor to a relapsing tumor in one patient.
Seven months after initial diagnosis, the primary tumor enlarged again, and a second biopsy from the enlarged lesion detected only adenocarcinoma with the L861Q mutation.